Historical Events
- May 1 First public flushing toilets the 'Monkey Closets' unveiled by George Jennings as part of The Great Exhibition at Hyde Park, London, costing one penny
- May 1 Great Exhibition opens in the Crystal Palace, at Hyde Park, London
- May 3 Sixth major fire in San Francisco destroys 1500-2000 buildings
- May 6 American physician and inventor John Gorrie patents a "refrigeration machine" to make ice
Yale Cylinder Lock
May 6 Linus Yale Jr. patents the Yale cylinder lock [1]
- May 6 New slave regulations go into effect in Suriname
- May 6 San Francisco Chamber of Commerce starts
- May 18 Amsterdam-Nieuwediep telegraph connection linked
1st Black Women's Rights Convention
May 29 Sojourner Truth addresses 1st Black Women's Rights Convention in Akron, Ohio
Famous Birthdays
- May 1 Laza Lazarević, Serbian writer (Prvi put s ocem na jutrenje) and psychiatrist, born in Šabac, Serbia (d. 1891)
- May 15 Herbert Lawford, British tennis player (Wimbledon 1887; first exponent of topspin), born in Bayswater, England (d. 1925)
- May 18 James Budd, American politician, Governor of California (1895-99), born in Janesville, Wisconsin (d. 1908)
- May 20 Emile Berliner, German inventor (flat phonograph record, founded Deutsche Grammophon), born in Hanover, Germany (d. 1929)
- May 20 Rose Hawthorne Lathrop, American nun and daughter of Nathaniel Hawthorne (founded Dominican Sisters of Hawthorne), born in Lenox, Massachusetss (d. 1926)
- May 21 Léon Bourgeois, French politician, French Prime Minister (1895-96, Nobel 1920), born in Paris, France (d. 1925)
- May 23 Antoni Stolpe, Polish pianist and composer, born in Pulawy, Poland (d. 1872)
- May 28 Dick Barlow, English cricket all-rounder (17 Tests, 2 x 50, 34 wickets, BB 7/40; Lancashire CCC), born in Bolton, England (d. 1919)